Unzip anywhere you like and just run the exe file.
Since there is absolutely no magic involved in the setup, this is
just as simple if you do not need start menu entries and full grown
uninstall support.

Just unpack and run. The only difference between the full packages
(above) and this minimal version is the lack of offline-help, the
exe will point you at the online help on the rawrite32 web site
instead. There is no functional drawback in using this variant.